Facebook is making big, immediate changes to News Feed. The company will now prioritize content from friends, family, and groups over “public content like posts from businesses, brands, and media,” CEO Mark Zuckerberg wrote in a post Thursday night. News publishers that have relied on Facebook for traffic will suffer: “Some news helps start conversations on important issues,” Zuckerberg wrote. “But too often today, watching video, reading news or getting a page update is just a passive experience.”

The change, Facebook admits, is major. Users will be given “more opportunities to interact with the people they care about,” which necessarily means less publisher content, Adam Mosseri, Facebook’s VP of News Feed, wrote in a post Thursday:

Because space in News Feed is limited, showing more posts from friends and family and updates that spark conversation means we’ll show less public content, including videos and other posts from publishers or businesses.

As we make these updates, Pages may see their reach, video watch time and referral traffic decrease. The impact will vary from Page to Page, driven by factors including the type of content they produce and how people interact with it. Pages making posts that people generally don’t react to or comment on could see the biggest decreases in distribution. Pages whose posts prompt conversations between friends will see less of an effect.

“News remains a top priority for us,” Campbell Brown, Facebook’s head of news partnerships, claimed in an email to large publishers, adding, “News stories shared between friends will not be impacted.”

this will mean a lot of things, but the first folks to feel this pain will almost certainly be publishers who rely on Facebook for distribution. I heard the word “video” quite a few times as something on the death list

It’s more about valuing stories that facilitate meaningful interactions between people. As it turns out people interact more with stories from friends than from publishes, and so on average friends and groups see gains and publishers see less distribution.

It’s worth noting that a lot of people were already not seeing much news in their feeds anyway. Last month my colleague Shan Wang published the results of an experiment she ran: “Half the people in our survey saw no news at all in the first 10 posts in their feeds — even using an extremely generous definition of ‘news’ that counted everything from celebrity gossip to sports scores to history-based explainers, across all mediums.” She wrote:

It may be that millions of people see certain news posts. But what’s filling the rest of their feeds is very likely less news than we, the industry that produces the news stories, like to think. After all, Facebook isn’t exactly hiding the fact that in the news feed, family and friends and sharing come first.

Also, personal anecdata: I’m active in a number of private Facebook groups and, for at least the past couple of months, I have pretty much only seen posts from those groups in my News Feed.

These changes will probably not seem drastic to many users. And many publishers have already noticed a decrease in organic Facebook traffic over the last year or so. Still, Thursday’s news probably cancels the plans of anyone who’d somehow thought they were going to build a business on Facebook traffic.

The summary slide on my @BostonGlobe 2017 strategy deck doesn't include anything re: Facebook pages. Pages are ineffective as they don't cultivate community and relationships. We've known this for years. pic.twitter.com/9bj47VS5PB